Types and localization of adnate seeds in sunflower heads

Results of sunflower head morphology study of modern sunflower varieties and hybrids in relation to adnate seeds localization are presented. It is shown that adnate seeds formation in embryo head begins at the budding (“star”) stage in 13-14 rows from head edge. In the head’s centre enclosed by adnate seeds the spiral organization of center zone breaks and seeds arrange disorderly. For the first time were discovered two types of seed adnation: accrete ovary with free corolla and adnate ovary and corolla. After sunflower seeds cleaning and calibration the number of adnate seeds is bigger in commercial sets of confectionary variety than in oil hybrid sets. But in both cases their quantity is not enough for considerable influence on plant density in future crops.